adjusted default certificate paths
Since Fedora 19, update-ca-trust script is used to regenerate
certificates used in validation for ssl connections. Directories like
/etc/ssl/certs do not contain symlinks named with hashes of certificates
they point to. One file containing bundled ca certificates is used
ssl_verify_host patch has been tweaked a bit, so that pywbem correctly
finds the right place with ca certifiactes - either single file on f19+
or a directory on older distributions.